A "clean" strop should remove little or no metal. But remember that even if we do not intentionally apply abrasives to a strop, it can pick up dust particles from the air and the dust can be rather large abrasives capable of removing metal. The surface of a latigo strop is more porous that some of the smoother types of leather, so it may have some dust particles embedded that are not readily apparent.

I suggest you get a helper to pull your hanging strop to normal taughtness and then check the flatness of your strop from side to side at various positions along the length of the strop. If the leather or cloth is tight in the middle and slack on the edges, the middle will have greater effect on the blade. Over time, this could cause uneven wear. A 3" wide strop is more likely to have such variations in tension than a 2 1/2" strop. Furthermore, those who use a 3" strop tend to use straight strokes rather than an X-strokes, so the blade will contact the same portion of the strop time after time.

Another factor may be that Dovo blades are honed on a convex ground coticule rather than a flat stone. While a convex stone is idea for honing a smiling blade, if the grind already has a slight frown, the convex hone may make the frown worse. Thus, it is possible your blade had a slight frown from the start, but you never checked it against a straight edge.